Method of fabricating semiconductor device

1. A method of fabricating a semiconductor device comprising the steps of:

forming an device isolation region in a substrate to divide a diffusion region into a first and a second diffusion regions;

forming a film to be processed on the substrate;

forming a hard mask layer and a first resist layer on the film to be processed;

forming a first pattern on the first resist layer;

etching the hard mask layer by using the first pattern as a mask;

forming a second resist layer on the hard mask layer;

forming a second pattern including a first space on the second resist layer for isolating the first pattern;

forming a third pattern including a second space shrunk from the first space on the hard mask layer by carrying out size conversion etching by using the second pattern formed on the second resist layer as a mask; and

etching the film to be processed by using the third pattern formed on the hard mask layer,

wherein the third pattern is a gate electrode pattern.

2. The method of fabricating a semiconductor device according to claim 1 , wherein the second space is formed in an device isolation region between the first and second diffusion regions.

3. The method of fabricating a semiconductor device according to claim 1 , wherein an anti-reflective coating film is formed on the hard mask layer.

4. The method of fabricating a semiconductor device according to claim 1 , wherein the hard mask layer comprises a material selected from the group consisting of SiOC, SiO2, SiON, SiN, SiC, SiOF and SiCN.

5. The method of fabricating a semiconductor device according to claim 1 , wherein etching gas used in the etching the hard mask layer is fluorocarbon gas expressed by CxHyFz (x=1 to 5, y=0 to 3, z=1 to 8) or its mixture.

6. The method of fabricating a semiconductor device according to claim 5 , wherein the fluorocarbon gas is selected from the group consisting of CHF3 and CH2F2.

7. The method of fabricating a semiconductor device according to claim 5 , wherein the etching gas further includes a gas selected from the group consisting of He, Ar, O2, N2 and CF4.

8. A method of fabricating a semiconductor device, comprising:

forming a device isolation region in a substrate;

forming a film to be processed on the substrate;

forming a hard mask layer on the film to be processed;

forming a first pattern in the hard mask layer;

forming a resist layer on the first pattern;

forming a second pattern including a first space in the resist layer, the first space being overlapped with the device isolation region;

etching the hard mask layer to form a third pattern including a second space shrunk from the first space by using the second pattern formed in the resist layer as a mask; and

etching the film to be processed by using the hard mask layer including the first pattern and the third pattern.

9. The method of fabricating a semiconductor device according to claim 8 , wherein the film to be processed is a conductive film.

10. The method of fabricating a semiconductor device according to claim 8 , wherein a space between each the first pattern is larger than the second space.

11. The method of fabricating a semiconductor device according to claim 8 , wherein the third pattern is a gate electrode pattern.

12. A method of fabricating a semiconductor device, comprising:

forming a device isolation region in a substrate;

forming a film to be processed on the substrate;

forming a hard mask layer on the film to be processed;

forming a first pattern in the hard mask layer;

forming a resist layer on the first pattern;

forming a second pattern including a first space in the resist layer;

etching the hard mask layer to form a third pattern including a second space shrunk from the first space by using the second pattern formed in the resist layer as a mask; and

etching the film to be processed by using the hard mask layer including the first pattern and the third pattern.